Lung cancer is the leading cause of cancer mortality in the United States. Ethnic differences in lung cancer occurrence and survival are inadequately understood and may reflect both environmental and genetic influences. Elucidating the interplay of these factors in very high- and very low-risk populations will be crucial in developing novel intervention and prevention strategies. This study focuses on African-Americans who bear a disproportionate burden of lung cancer and Latinos who have very low rates. The investigators state that this continuation of their ecogenetics study of lung cancer in Houston, TX, will test specific findings from the first study in a large population of African-Americans and Latinos in Northern California and will explore gene loci never before studied in minorities. They will collect blood specimens and conduct in-person interviews with 350 cases from each ethnic group, identified through the Northern California Cancer Center (NCCC) rapid case ascertainment program, and an equal number of ethnicity-, age-, and sex-frequency matched controls recruited through random digit dialing. They will establish a DNA bank and estimate the prevalence of genetic polymorphisms in a cytochrome P-450 gene (CYP1A1), two glutathione S-transferases (GSTM1, GSTT1), the NAD(P)H:quinone oxidoreductase (NQ01) and two N-acetyl transferases (NAT1, NAT2), and the XRCC1 DNA repair gene. The investigators state that previous associations of these traits with lung cancer among Caucasians or Japanese are not readily generalizable to minorities without the further detailed study that they propose here. Using multiple genetic markers is a highly efficient means to simultaneously test several hypotheses concerning genetic contributions to cancer risk. They further state that an especially unique contribution will be laying the foundation to understand the markedly lower rates of lung cancer among Latino populations; they emphasize that their study represents the only population-based study of its kind among Latinos. Furthermore, they state that this will be only the second population-based genetic epidemiologic study of lung cancer in African-Americans; African-American men in California have an 11% lifetime risk of lung cancer. The further note that the DNA bank and comprehensive questionnaire data on smoking and other important risk factors also will prove invaluable for continuing studies of the genetic epidemiology of lung cancer.